Preclinical evaluation of the supercritical extract of azadirachta indica (neem) leaves in vitro and in vivo on inhibition of prostate cancer tumor growth

Integrins and Actions of Androgen in Breast Cancer

Androgen has been shown to regulate male physiological activities and cancer proliferation. It is used to antagonize estrogen-induced proliferative effects in breast cancer cells. However, evidence indicates that androgen can stimulate cancer cell growth in estrogen receptor (ER)-positive and ER-negative breast cancer cells via different types of receptors and different mechanisms. Androgen-induced cancer growth and metastasis link with different types of integrins. Integrin αvβ3 is predominantly expressed and activated in cancer cells and rapidly dividing endothelial cells. Programmed death-ligand 1 (PD-L1) also plays a vital role in cancer growth. The part of integrins in action with androgen in cancer cells is not fully mechanically understood. To clarify the interactions between androgen and integrin αvβ3, we carried out molecular modeling to explain the potential interactions of androgen with integrin αvβ3. The androgen-regulated mechanisms on PD-L1 and its effects were also addressed.

Methanolic neem (Azadirachta indica) stem bark extract induces cell cycle arrest, apoptosis and inhibits the migration of cervical cancer cells in vitro

Background

Cervical cancer remains one of the significant causes of mortality in women due to the limitations of current treatment strategies and their associated side effects. Investigation of alternative medicine, including phytomedicine, has shown effective anti-cancer potential with fewer side effects. Azadirachta indica (commonly known as neem) is known for its medicinal properties. The present study investigated the anti-cancer potential of methanolic neem stem bark extract (MNBE) against cervical cancer using HeLa, SiHa, and ME-180 cell lines.

Methods

Cytotoxic effect of MNBE on cultured cell lines was evaluated by MTT and clonogenic assay. The growth-inhibiting effect of MNBE was further confirmed by performing cell cycle analysis and apoptosis assay using flow cytometry. The anti-migratory effect of MNBE was evaluated by using wound healing and Boyden chamber assay. Real-time PCR was used to determine the mRNA expression, and western blot and flow cytometry was used to determine the protein levels of growth and migration-related genes.

Results

MNBE significantly suppressed the growth and survival of cervical cancer cells in a dose-dependent manner by inducing cell cycle arrest and apoptosis. In addition, the growth inhibitory effect of MNBE was specific to cervical cancer cells than normal cells. Cell cycle arrest was correlated to transcriptional downregulation of cyclin dependent kinase 1 (CDK1), cyclin A, and cyclin B. Additionally, MNBE treatment resulted in the upregulation of active caspase-3 protein and downregulation of prosurvival genes, Bcl2, and survivin at mRNA level and NFkB-p65 at the protein level. Furthermore, MNBE inhibited the migration of cervical cancer cells accompanied by modulation of migration-related genes, including zona occludens-1 (ZO-1), matrix metalloproteinase 2 (MMP2), focal adhesion kinase (FAK), N-cadherin, snail, and E-cadherin.

Conclusion

In summary, the present study provides the first evidence of MNBE in restricting cervical cancer cell growth and migration, which warrants further investigation for developing novel anti-cancer drugs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03718-7.

The anti-cancer properties of neem (Azadirachta indica) through its antioxidant activity in the liver: its pharmaceutics and toxic dosage forms. A literature review

OBJECTIVES

The neem (Azadirachta indica) have been used in herbal medicine for the treatment of multiple diseases, particularly cancer. The mechanism of anti-cancer properties of neem are far from clear. However, it is well accepted that anti-cancer effects of neem is mediated via its hepatic anti-oxidant activity. In the present review, we are going to classify in vitro and in vivo studies about anti-cancer activity of neem via its hepatic anti-oxidant activity. We also summarize its active ingredients and some therapeutic and toxic dosage forms.

METHODS

A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, as well as Google Scholar pre-print database using all available MeSH terms for neem, A. indica, anti-cancer, anti-tumor, carcinogen, liver, antioxidant activity, neem ingredients, and glutathione. Electronic database searches combined and duplicates were removed.

RESULTS

The neem plant have been used in herbal medicine for the treatment of various diseases, particularly cancer. The mechanisms of anti-cancer effects of neem are far from clear. Cancerous cells growth can induce imbalance the oxidant and anti-oxidant activity in various organs particularly in the liver. Therefore, it seems that neem have anti-cancer effects via restore of the antioxidant disturbances close to the control ones in the liver. Additionally, administration of neem extract can induce oncostatic potential via several mechanism including; suppression of the NF-κβ pathway, increased expression of tumor suppressor (such as p53 and pTEN), decreased expression of oncogenes (such as c-Myc), and increased apoptosis in cancerous cells. The median lethal dose (LD50) value for extracts of neem was higher than 2,500 mg/kg.

CONCLUSIONS

It is suggested that neem plays pivotal role in the prevention and treatment of cancer via its hepatic antioxidant activity. Indeed, application of neem extract can decreased tumor growth via restore of the antioxidant disturbances close to the control ones in the liver.

Prostate cancer: Therapeutic prospect with herbal medicine

Prostate cancer (PCa) is a major cause of morbidity and mortality in men worldwide. A geographic variation on the burden of the disease suggested that the environment, genetic makeup, lifestyle, and food habits modulate one's susceptibility to the disease. Although it has been generally thought to be an older age disease, and awareness and timely execution of screening programs have managed to contain the disease in the older population over the last decades, the incidence is still increasing in the population younger than 50. Existing treatment is efficient for PCa that is localized and responsive to androgen. However, the androgen resistant and metastatic PCa are challenging to treat. Conventional radiation and chemotherapies are associated with severe side effects in addition to being exorbitantly expensive. Many isolated phytochemicals and extracts of plants used in traditional medicine are known for their safety and diverse healing properties, including many with varying levels of anti-PCa activities. Many of the phytochemicals discussed here, as shown by many laboratories, inhibit tumor cell growth and proliferation by interfering with the components in the pathways responsible for the enhanced proliferation, metabolism, angiogenesis, invasion, and metastasis in the prostate cells while upregulating the mechanisms of cell death and cell cycle arrest. Notably, many of these agents simultaneously target multiple cellular pathways. We analyzed the available literature and provided an update on this issue in this review article.

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Prostate cancer in a major cause of death in older population worldwide.

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Efficacies of current treatment options are limited in many cases.

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Phytochemicals and extracts isolated from plants show anti-prostate cancer activity with unique mechanisms.

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Certain phytochemicals alone or in combination with current chemotherapy show therapeutic promise.

Leelamine suppresses cMyc expression in prostate cancer cells in vitro and inhibits prostate carcinogenesis in vivo

Aim

Leelamine (LLM) inhibits growth of human prostate cancer cells but the underlying mechanism is not fully understood. The present study was undertaken to determine the effect of LLM on cMyc, which is overexpressed in a subset of human prostate cancers.

Methods

The effect of LLM on cMyc expression and activity was determined by western blotting/confocal microscopy and luciferase reporter assay, respectively. A transgenic mouse model of prostate cancer (Hi-Myc) was used to determine chemopreventive efficacy of LLM.

Results

Exposure of androgen sensitive (LNCaP) and castration-resistant (22Rv1) human prostate cancer cells to LLM resulted in downregulation of protein and mRNA levels of cMyc. Overexpression of cMyc partially attenuated LLM-mediated inhibition of colony formation, cell viability, and cell migration in 22Rv1 and/or PC-3 cells. LLM treatment decreased protein levels of cMyc targets (e.g., lactate dehydrogenase), however, overexpression of cMyc did not attenuate these effects. A trend for a decrease in expression level of cMyc protein was discernible in 22Rv1 xenografts from LLM-treated mice compared with control mice. The LLM treatment (10 mg/kg body weight, 5 times/week) was well-tolerated by Hi-Myc transgenic mice. The incidence of high-grade prostatic intraepithelial neoplasia, adenocarcinoma in situ, and microinvasion was lower in LLM-treated Hi-Myc mice but the difference was not statistically significant.

Conclusion

The present study reveals that LLM inhibits cMyc expression in human prostate cancer cells in vitro but concentrations higher than 10 mg/kg may be required to achieve chemoprevention of prostate cancer.

Molecular Basis of Prostate Cancer and Natural Products as Potential Chemotherapeutic and Chemopreventive Agents

Prostate cancer is the second most common malignant cancer in males. It involves a complex process driven by diverse molecular pathways that closely related to the survival, apoptosis, metabolic and metastatic characteristics of aggressive cancer. Prostate cancer can be categorized into androgen dependent prostate cancer and castration-resistant prostate cancer and cure remains elusive due to the developed resistance of the disease. Natural compounds represent an extraordinary resource of structural scaffolds with high diversity that can offer promising chemical agents for making prostate cancer less devastating and curable. Herein, those natural compounds of different origins and structures with potential cytotoxicity and/or in vivo anti-tumor activities against prostate cancer are critically reviewed and summarized according to the cellular signaling pathways they interfere. Moreover, the anti-prostate cancer efficacy of many nutrients, medicinal plant extracts and Chinese medical formulations were presented, and the future prospects for the application of these compounds and extracts were discussed. Although the failure of conventional chemotherapy as well as involved serious side effects makes natural products ideal candidates for the treatment of prostate cancer, more investigations of preclinical and even clinical studies are necessary to make use of these medical substances reasonably. Therefore, the elucidation of structure-activity relationship and precise mechanism of action, identification of novel potential molecular targets, and optimization of drug combination are essential in natural medicine research and development.

Are polyphenol antioxidants at the root of medicinal plant anti-cancer success?

ETHNOPHARMACOLOGICAL RELEVANCE

Given the severe side effects associated with most of the conventional cancer medications, as well as the expanding body of evidence indicating secondary toxicity of these drugs, individuals with cancer are increasingly turning to natural alternatives. Similarly, the pharmaceutical industry is in search of natural products to treat cancer. An understanding of the specific active components in plant products with which anti-cancer efficacy is achieved is required for this research to move forward.

AIM OF THE STUDY

To integrate data from cancer-relatestudies on plant-derived products or extracts, to elucidate whether these products may have similar active ingredients and/or mechanisms of action, that can explain their efficacy. This review also includes a discussion of the methodological complexities and important considerations involved in accurate isolation and characterisation of active substances from plant material.

CONCLUSIONS

From the literature reviewed, most plant products with consistently reported anti-cancer efficacy contains high levels of polyphenols or other potent antioxidants and their mechanisms of action correlate to that reported for isolated antioxidants in the context of cancer. This suggests that natural products may indeed become the panacea against this chronic disease - either as therapeutic medicine strategy or to serve as templates for the design of novel synthetic drugs. The recommendation is made that antioxidant activity of plant actives and especially polyphenols, should be the focus of anti-cancer drug discovery initiatives. Lastly, researchers are advised to exploit current techniques of chemical compound characterisation when investigating polyphenol-rich plants to enable the easy consolidation of research findings from different laboratories.

Protective Effect of Sika Deer (Cervus nippon) Velvet Antler Extract against Cisplatin-Induced Kidney and Liver Injury in a Prostate Cancer PC-3 Cell Xenograft Model

We previously discovered the antioxidant and antiprostate cancer effects of antler extract (AE), but whether it inhibits cisplatin- (Cis-) induced toxicity has not been investigated. In this study, the effect of AE on Cis-induced side effects in the kidney and liver using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide-based cytotoxicity and cell cycle assays in prostate cancer PC-3 cells in vitro is investigated. Furthermore, we used a xenograft mouse model of the same cells to examine the in vivo effects and mechanisms of action. Cis and Cis + AE treatment attenuated prostate cancer cell growth by inducing apoptosis in vitro. Cis + AE stimulated cleaved caspases 3, 7, and 9 and polyadenosine diphosphate ribose polymerase expression. Cis + AE treatment for 1 week significantly increased the superoxide dismutase and catalase antioxidant activity while thiobarbituric acid reactive substances decreased. The histopathological damage and tumor necrosis factor-α, interleukin- (IL-) 1β and IL-6, cyclooxygenase-2, and inducible nitric oxide synthase expression in the kidney and liver tissue decreased. Therefore, AE likely possesses antiprostate cancer activity and inhibits Cis toxicity.

Nimbolide induced apoptosis by activating ERK-mediated inhibition of c-IAP1 expression in human hepatocellular carcinoma cells

Nimbolide is one of the major compounds from the leaves and flowers of the neem tree and exhibits antitumor properties on various cancer cells. However, no report has shown that nimbolide induces apoptosis in vitro and in vivo in human hepatocellular carcinoma cells. Our results indicated that it inhibited cell growth in Huh-7 and PLC/PRF/5 cells. We also found that nimbolide induced cell death through the induction of G2/M phase arrest and mitochondrial dysfunction, accompanied by the increased expression of cleaved caspase-7, caspase-9, caspase-3, caspase-PARP, and Bax and decreased expression of Mcl-1 and Bcl-2. A human apoptosis antibody array analysis demonstrated that inhibition of the apoptosis family proteins (XIAP, c-IAP1, and c-IAP2) was one of the major targets of nimbolide. Additionally, nimbolide sustained activation of ERK expression. Moreover, pretreatment with U0126 (MEK inhibitor) markedly abolished nimbolide-inhibited cell viability, induced cell apoptosis, ERK phosphorylation, cleaved caspase-9, caspase-3, cleaved-PARP activation, and increased c-IAP1 expression in Huh-7 cells. An in vivo study showed that nimbolide significantly reduced Huh-7 tumor growth and weight in a xenograft mouse model. This study indicated the antitumor potential of nimbolide in human hepatocellular carcinoma cells.

Simultaneous determination of five azadirachtins in the seed and leaf extracts of Azadirachta indica by automated online solid-phase extraction coupled with LC-Q-TOF-MS

Neem (Azadirachta indica) extract is well-known as a natural pesticide for the control of agricultural pests. Azadirachtin A and its structural analogues are considered as active compounds. However, the amounts of azadirachtins varies in neem extracts, providing a variety of insecticidal activities. In this study, a novel method of automated online solid-phase extraction coupled with liquid chromatography/quadrupole-time-of-flight mass spectrometry (SPE-LC–Q-TOF–MS) was developed and validated for simultaneous quantification of five azadirachtins (azadirachtins A, B, D, H and I) in seed and leaf extracts of A. indica. Different experimental parameters (such as SPE cartridge, injection volume and washing step) were optimized. The optimized SPE-LC–Q-TOF–MS method showed good recovery (82.0–102.8%), linearity (r² ≥ 0.9991) and precision (0.83–4.83%). The limit of detections (LODs) for the five analytes ranged from 0.34 to 0.76 ng mL⁻¹. The validated method was successfully applied for determination of the analytes in the neem leaves and seeds from different locations and a neem formulation. The online SPE-LC–Q-TOF–MS method was found to be a simple, precise and accurate and can be used as a powerful tool for quality control of neem extracts or its formulations.

Ethanolic Extracts from Azadirachta indica Leaves Modulate Transcriptional Levels of Hormone Receptor Variant in Breast Cancer Cell Lines

Breast Cancer (BC) encompasses numerous entities with different biological and behavioral characteristics, favored by tumor molecular complexity. Azadirachta indica (neem) presents phenolic compounds, indicating its potential as an antineoplastic compound. The present study aimed to evaluate the cellular response of MCF10, MCF7, and MDA-MB-231 breast cell lines to ethanolic extracts of neem leaves (EENL) obtained by dichloromethane (DCM) and ethyl acetate (EA) solvent. Extracts’ antiproliferative activities were evaluated against MCF 10A, MCF7, and MDA-MB-231 for 24 and 48 h using MTT assay. ESR1, ESR2, AR, AR-V1, AR-V4, and AR-V7 transcripts were quantified through qPCR for 0.03125 μg/mL of DCM and 1.0 μg/mL for EA for 48 h. The EENL was tested on Drosophila melanogaster as a sole treatment and then also together with doxorubicin. Antiproliferative effect on tumor cell lines without affecting MCF 10A were 1.0 µg/mL (P < 0.001) for EA, and 0.03125 µg/mL (P < 0.0001) for DCM, both after 48 h. Transcriptional levels of AR-V7 increased after treatment. In vivo assays demonstrated that EENL induced fewer tumors at a higher concentration with doxorubicin (DXR). The behavior of AR-V7 in the MDA-MB-231 tumor lineage indicates new pathways involved in tumor biology and this may have therapeutic value for cancer.

Comparison of Two Adsorbent Based de-Bittering Procedures for Neem (Azadirachta indica A. Juss) Tea- Effect on Polyphenols, Anti-Oxidant Capacity, Color and Volatile Profile

Bitterness reduction, especially of foods and beverages containing phytonutrients, is one of the biggest challenges in the food industry because bitterness has a deleterious effect on the taste profile of foods and beverages. Neem (Azadirachta indica A. Juss) is a medicinal tree, indigenous to the Indian-subcontinent, whose medicinal properties have led to it being heralded as the tree which is the "panacea for all diseases". However, neem leaf is extremely bitter, in large part due to its limonoid content, making it unpalatable. The objective of this study was to apply two adsorbent based strategies, namely solid phase extraction (SPE) and Amberlite XAD-16 (AMB) resin, to achieve de-bittering of neem tea and to determine the effects of the de-bittering on the bio-active, color and volatile properties. The solid SPE treatment completely removed the flavonol, quercetin, from neem tea while in Amberlite XAD-16 treated tea (AMB) it was only insignificantly (p > 0.05) reduced. We also observed decreases in total phenolic content and consequently anti-oxidant activities after de-bittering. A 62% mean reduction of limonoid aglycones indicated diminished levels of bitterness. The loss of phenolics lead to a visually appreciable color changes in the treated teas. The de-bittering also leads to a loss of sesquiterpenes, ketones and acids from neem tea. In conclusion, we found that while SPE cartridges were more efficient in removing bitterness, they caused a greater reduction in bio-active compounds than AMB XAD-16 resins, which may ultimately affect the health properties of neem tea.

Nimbolide-Induced Oxidative Stress Abrogates STAT3 Signaling Cascade and Inhibits Tumor Growth in Transgenic Adenocarcinoma of Mouse Prostate Model

AIMS

Prostate cancer (PCa) is one of the most commonly diagnosed cancers worldwide. Currently available therapies for metastatic PCa are only marginally effective, hence novel treatment modalities are urgently required. Considerable evidence(s) suggest that deregulated activation of oncogenic transcription factor, signal transducer and activator of transcription 3 (STAT3) plays a pivotal role in the development and progression of PCa. Thus, agents that can abrogate STAT3 activation could form the basis of novel therapy for PCa patients. In the present study, we analyzed whether the potential anticancer effects of nimbolide (NL), a limonoid triterpene derived from Azadirachta indica, against PCa cell lines and transgenic adenocarcinoma of mouse prostate (TRAMP) model are mediated through the negative regulation of STAT3 pathway.

RESULTS

Data from the in vitro studies indicated that NL could significantly inhibit cell viability, induce apoptosis, and suppress cellular invasion and migration. Interestingly, NL also abrogated STAT3 activation and this effect was found to be mediated via an increased production of reactive oxygen species (ROS) due to GSH/GSSG imbalance. Oral administration of NL significantly suppressed the tumor growth and metastasis in TRAMP mouse model without exhibiting any significant adverse effects.

INNOVATION

The present study demonstrates the critical role of GSH/GSSG imbalance-mediated ROS production contributing to the STAT3 inhibitory and tumor-suppressive effect of NL in PCa.

CONCLUSION

Overall, our findings indicate that NL exhibits significant anticancer effects in PCa that may be primarily mediated through the ROS-regulated inhibition of STAT3 signaling cascade.

Anticancer effects of adenovirus-mediated calreticulin and melanoma-associated antigen 3 expression on non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is highly prevalent and needs novel therapies. Melanoma-associated antigen 3 (MAGE-A3) is a lung cancer antigen and calreticulin (CALR) can modulate immune responses. Our previous study has shown that up-regulated MAGE-A3 and CALR expression inhibits the proliferation and invasion of glioma cells. In this study, we examined the effect of adenovirus (Ad)-mediated MAGE-A3 and/or CALR expression on the proliferation, invasion, and apoptosis of human NSCLC cells and on the vascular tube formation of human endothelial cells as well as on dendritic cell (DC) activation and induced CD8(+) cytotoxic T lymphocyte (CTL) activity in vitro. We found that low levels of CALR and MAGE-A3 were expressed by A549 cells, but only very low CALR was expressed by DC. Up-regulated CALR and MAGE-A3 expression by infection with Ad-CALR/MAGE-A3 significantly inhibited the proliferation and invasion, but promoted the apoptosis of A549 cells. Up-regulated CALR and MAGE-A3 expression significantly inhibited cyclin D1 expression and the AKT, ERK1/2 and NF-κB expression and phosphorylation in A549 cells. Up-regulated CALR expression inhibited the tube formation in human endothelial cells. Up-regulated CALR and MAGE-A3 expression synergistically enhanced classical DC activation by enhancing IL-12, but reducing IL-10 secretion. Furthermore, CTLs induced by up-regulated CALR and MAGE-A3 expressing DCs synergistically triggered A549 cell apoptosis, which was abrogated by treatment with anti-HLA I, but not anti-HLA II antibodies. Moreover, CTLs induced by CALR and MAGE-A3-expressing DCs had a higher frequency of A549-specific IFN-γ-secreting T cells. Our data indicated that up-regulated CALR and MAGE-A3 expression inhibited the carcinogenesis of NSCLC by modulating the AKT, ERK MAPK and NF-κB signaling and enhanced classical DC activation and MAGE-A3-specific CTL cytotoxicity. Therefore, our findings may provide new insights in understanding the role of CALR in modulating antigen-specific T cell immunity and may aid in the design of new therapies for NSCLC.

Nimbolide targets BCL2 and induces apoptosis in preclinical models of Waldenströms macroglobulinemia

Neem leaf extract (NLE) has medicinal properties, which have been attributed to its limonoid content. We identified the NLE tetranorterpenoid, nimbolide, as being the key limonoid responsible for the cytotoxicity of NLE in various preclinical models of human B-lymphocyte cancer. Of the models tested, Waldenströms macroglobulinemia (WM) cells were most sensitive to nimbolide, undergoing significant mitochondrial mediated apoptosis. Notably, nimbolide toxicity was also observed in drug-resistant (bortezomib or ibrutinib) WM cells. To identify putative targets of nimbolide, relevant in WM, we used chemoinformatics-based approaches comprised of virtual in silico screening, molecular modeling and target–ligand reverse docking. In silico analysis revealed the antiapoptotic protein BCL2 was the preferential binding partner of nimbolide. The significance of this finding was further tested in vitro in RS4;11 (BCL2-dependent) tumor cells, in which nimbolide induced significantly more apoptosis compared with BCL2 mutated (Jurkat BCL2^Ser70-Ala) cells. Lastly, intraperitoneal administration of nimbolide in WM tumor xenografted mice, significantly reduced tumor growth and IgM secretion in vivo, while modulating the expression of several proteins as seen on immunohistochemistry. Overall, our data demonstrate that nimbolide is highly active in WM cells, as well as other B-cell cancers, and engages BCL2 to exert its cytotoxic activity.

Neem components as potential agents for cancer prevention and treatment

Azadirachta indica, also known as neem, is commonly found in many semi-tropical and tropical countries including India, Pakistan, and Bangladesh. The components extracted from neem plant have been used in traditional medicine for the cure of multiple diseases including cancer for centuries. The extracts of seeds, leaves, flowers, and fruits of neem have consistently shown chemopreventive and antitumor effects in different types of cancer. Azadirachtin and nimbolide are among the few bioactive components in neem that have been studied extensively, but research on a great number of additional bioactive components is warranted. The key anticancer effects of neem components on malignant cells include inhibition of cell proliferation, induction of cell death, suppression of cancer angiogenesis, restoration of cellular reduction/oxidation (redox) balance, and enhancement of the host immune responses against tumor cells. While the underlying mechanisms of these effects are mostly unclear, the suppression of NF-κB signaling pathway is, at least partially, involved in the anticancer functions of neem components. Importantly, the anti-proliferative and apoptosis-inducing effects of neem components are tumor selective as the effects on normal cells are significantly weaker. In addition, neem extracts sensitize cancer cells to immunotherapy and radiotherapy, and enhance the efficacy of certain cancer chemotherapeutic agents. This review summarizes the current updates on the anticancer effects of neem components and their possible impact on managing cancer incidence and treatment.